Mobile devices, such as mobile phones, are becoming increasingly popular. Such devices are often provided with wireless communications capabilities. In wireless communications, dipole antennas are well-known and have been used in various applications, such as “rabbit ears” in television set; in FM radio broadcast receivers, and in radar and military, etc.
For the forthcoming fifth generation (5G) cellular standard, millimeter wave antennas are a potential solution. Moreover, as the demand for a higher bandwidth increases, the 3GPP and other standing committees will undoubtedly establish a fifth generation mobile communications standard in an operating frequency range higher than the current third and fourth generation wireless standards. In the potential millimeter wave operating frequencies, antennas can be fabricated on-chip or on-package to reduce overhead costs. Dipole antenna is a strong candidate for millimeter wave on-chip/on-package antennas. Although dipole antenna is suitable in millimeter wave antenna designs, it suffers from a narrow bandwidth and is less adequate for wide bandwidth applications.